Multi-mode variable cam timing phaser

Patent metadata

Field	Value
Publication number	US-9803520-B2
Application number	US-201615146520-A
Country	US
Kind code	B2
Filing date	May 4, 2016
Priority date	Aug 31, 2015
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A variable camshaft timing device can operate using pressure generated by camshaft torque energy to transfer fluid from one working chamber to another work chamber or operate via an external fluid pressure source to fill one working chamber while simultaneously exhausting an opposing working chamber or operate using both modes simultaneously. The mode of the variable camshaft timing device is determined by the position of the control valve. The lock pin is controlled by fluid from one of the working chambers.

First claim

What is claimed is:

1. A variable cam timing phaser for an internal combustion engine including a housing assembly with an outer circumference for accepting drive force and a rotor assembly having at least one vane, the rotor assembly being coaxially located within the housing for connection to a camshaft, wherein the housing assembly and the rotor assembly define at least one vane chamber, the vane within the vane chamber acting to shift relative angular position of the housing assembly and the rotor assembly when fluid is supplied to the first chamber or the second chamber, the phaser comprising:
a control valve for directing fluid from a fluid input to and from the first chamber and the second chamber through a first chamber line, a second chamber line, and a supply line coupled to the fluid input, the control valve comprising:
a hollow sleeve with a plurality of ports, where at least two of the ports are connected by a first recess and at least two other ports are connected by a second recess;
a spool received within the hollow sleeve comprising:
a plurality of lands for selectively blocking the plurality of ports of the hollow sleeve;
a working central passage located within the spool;
an inlet passage located within the spool;
a recirculation check valve received within the working central passage, limiting the flow of fluid between the first and second chambers through the working central passage;
an inlet check valve received within the inlet central passage, allowing fluid from the fluid input to flow to the first and second chambers, and preventing flow from the first and second chambers to the fluid input during cam torque reversals;

the control valve being movable between positions wherein the phaser operates in a plurality of modes under control of the control valve, the modes comprising:
a first mode using cam torque to move the vane in a first direction, in which fluid from the first chamber is recirculating to the second chamber through the recirculation check valve;
a second mode using cam torque to move the vane in the second direction, in which fluid from the second chamber is recirculated to the first chamber through the recirculation check valve;
a third mode for holding the phaser in position, in which fluid is routed to the first and the second chambers from the fluid input through the inlet check valve of the spool;
wherein in the first mode and second mode, makeup fluid is supplied from the fluid input to one of the first chamber or the second chambers through the inlet check valve of the spool; and
wherein in the third mode, makeup fluid is supplied from the fluid input to both the first chamber and the second chamber through the inlet check valve of the spool.

2. The phaser of claim 1 , wherein the control valve further comprising a hollow center bolt with a bore for receiving the sleeve and the spool.

3. The phaser of claim 2 , wherein the first recess and the bore of center bolt form a passage in fluid communication with a lock pin.

4. The phaser of claim 3 , wherein the lock pin is slideably located in the rotor assembly or the housing assembly, the lock pin being moveable by fluid from the fluid input from a locked position in which an end portion engages a recess, locking the relative angular position of the housing assembly and the rotor assembly, to an unlocked position, in which the end portion does not engage the recess;
wherein when the control valve is in the position for the first mode, the lock pin is moved to the locked position;
wherein when the control valve is not in the position for the first mode, the lock pin is moved to the unlocked position.

5. The phaser of claim 1 , wherein recirculation check valve comprises a plate, a plug, and a spring with a first end attached to the plate and a second end attached to the plug.

6. The phaser of claim 1 , wherein the inlet check valve comprises a ball, a plug, and a spring with a first end attached to the ball and a second end attached to the plug, wherein the ball blocks the flow of fluid through a passage connected to the inlet passage.

7. The phaser of claim 1 , further comprising a lock pin slideably located in the rotor assembly or the housing assembly, the lock pin being moveable by fluid provided by the fluid input from a locked position in which an end portion engages a recess, locking the relative angular position of the housing assembly and the rotor assembly, to an unlocked position, in which the end portion does not engage the recess;
wherein when the control valve is in the position for the first mode, the lock pin is moved to the locked position;
wherein when the control valve is not in the position for the first mode, the lock pin is moved to the unlocked position.

8. The phaser of claim 1 , wherein the first chamber is an advance chamber and the second chamber is a retard chamber.

9. The phaser of claim 1 , wherein the first chamber is a retard chamber and the second chamber is an advance chamber.

Assignees

• Borgwarner Inc

Inventors

• Smith Franklin R
• Kenyon Brian T

Classifications

• F01L1/047

  Camshafts · CPC title

• F01L1/3442 Primary

  using hydraulic chambers with variable volume to transmit the rotating force · CPC title

• F01L2250/06

  the camshaft being driven by gear wheels · CPC title

• F01L2001/34426

  Oil control valves · CPC title

• F01L2250/04

  the camshaft being driven by belts · CPC title